 Historically,
the ocean has been viewed as a limitless resource that could
absorb any and all human impacts. The "Freedom of the Seas"
doctrine prevailed, holding that no limits should be placed
on navigation and resource exploitation because natural law
forbids ownership of things that seemed to be created for common
use. This doctrine was based on the assumption that ocean resources
could be used by one person or nation without impacting other
persons or nations.
It has become clear that marine resources are indeed finite
after all. Human activities such as shipping and resource extraction
are conducted on scales that do impact other persons and nations,
as well as the assimilative and productive capacity of the ocean
itself. Many tools have been employed to reduce adverse impacts
of human uses of the oceans, such as pollution, and to increase
the efficiency and sustainability of resource use. Some tools
are used to control inputs (e.g., fishing effort or capacity
controls, source reduction), some to control outputs (e.g.,
allowable catch limits, water quality standards), and others
to control access (e.g., limited entry programs, urban growth
limits, zoning).
Zoning is a tool for reducing conflicts, increasing resource
use efficiency and sustainability, and reducing adverse impacts
of human uses by separating incompatible uses spatially. Zoning
has been used for decades to separate incompatible uses on land,
such as factories and playgrounds, thereby reducing conflict.
Zoning has also long been used to facilitate commercial objectives
in the sea (e.g., shipping lanes, Exclusive Economic Zones).
This paper focuses on zoning to help achieve the somewhat more
recently articulated goals of protecting marine ecological integrity
and for enhancing fisheries management. Each item below describes
briefly how zoning could be used to achieve the stated objective.
1. Reducing impacts on sensitive species or communities (e.g.,
buffer zones around seabird colonies).
There is a need to create buffer zones around areas used by
sensitive populations of albatross (e.g., Midway Island), marine
mammals (e.g., Hawaiian monk seals; Stellar sea lions), and
sea turtles for many reasons. Buffer zones around sensitive
areas such as nesting or foraging sites kept relatively free
of debris could help sea turtles and marine mammals avoid entanglement
in nets, ingestion of plastic products, and other impacts associated
with debris. Such buffer zones may not be as helpful for albatross,
which forage far from their breeding places, returning "food"
(including such things as cigarette lighters) to their chicks.
To protect far ranging species such as albatross, and to address
the marine debris problem at its root, the production and dumping
of debris must be reduced, with a focus on eliminating or replacing
products that result in particularly harmful types of debris
(e.g., plastic light sticks used in the swordfish longline fishery,
cigarette lighters, nets) with biodegradable replacements.
There is also a need to establish precautionary buffer zones
around breeding colonies and in major feeding grounds of the
Stellar sea lion and other organisms that appear to be limited
by the availability of prey that is also exploited by humans.
While the hypothesis that pollock catch may reduce foraging
success of the sea lion and thus contribute to population decline
is still somewhat controversial, it should be tested by restricting
or eliminating fishing in several feeding areas, and carefully
monitoring prey availability, foraging success, and population
dynamics. There are strong indications that fledging success
of puffins and other bird species on the coast of Norway was
strongly limited by lack of prey, caused by overfishing of capelin
and other shoaling fishes by the reduction fishery. A scientific
review to identify species that may be limited by prey that
are also target (or major bycatch) species of fisheries would
help focus initiatives to establish such buffer areas.
2. Protecting biodiversity and habitats from the effects of
ship groundings and other direct threats.
These are straightforward benefits of marine protected areas,
which could exclude any or all threats, depending on priorities.
International Maritime Organization "Areas of Critical Concern",
federal marine sanctuaries, and state-designated marine protected
areas, as well as other measures, can all be used to achieve
protection from vessel groundings, oil drilling, and other direct
threats to marine ecosystems.
3. Protecting marine ecosystems from pollution.
While marine protected areas with restrictions on dumping and
discharge can benefit ecosystems within their boundaries, it
is quite common for major sources of pollution to be outside
the jurisdictional boundaries of marine protected areas. Once
MPA implementation has focused conservation attention on an
area, cooperative agreements or mandated pollution reduction
programs may become more feasible. Protecting ecosystems from
pollution requires a watershed and "solution area" approach,
since sources of pollution may be far removed from the waters
they ultimately impact. Source reduction, replacement of toxic
materials, and incentives for innovation will be required to
make such MPAs effective. Limits on pollution loading from a
watershed or solution area, coupled with an assignment of transferable
reduction requirements to major offenders, are likely to create
the kinds of incentives needed to achieve significant pollution
reduction at least cost.
4. Protecting against overfishing, helping to rebuild depleted
fish populations, and enhancing fisheries.
While no-take marine reserves clearly protect biodiversity (particularly
resident species), the effects of reserves on fisheries have
not been studied adequately to draw conclusions. No-take marine
reserves have been shown to help rebuild local fish populations
(particularly heavily exploited species) within reserves; and
it is reasonable to assume that larger populations of bigger,
more fecund fish within reserves should export juveniles and
larvae that should enhance fisheries "downstream". This anticipated
result is supported by some modeling studies. In addition, reserves
may help to improve access to multispecies fisheries that are
now constrained by bycatch (e.g., the west coast groundfish
fishery) by providing refuge to bycaught species. However, very
few empirical studies of fisheries enhancement by reserves have
been conducted.
More no-take reserves should be established in all of the biogeographic
regions of the US EEZ and state marine waters to determine whether
they can in fact enhance fisheries outside of reserve boundaries.
Policy needs to take into account displaced fishing capacity,
perhaps through capacity reduction programs (e.g., buy-outs,
ITQs, or very effective limited entry programs in which the
number of licenses granted is substantially less than the number
of fishers engaged in the fishery). Fishery management should
not be relaxed outside reserves when reserves are established,
when reserves are intended to hedge against uncertainty inherent
in fish population assessment and management (although increased
fishing mortality outside reserves may be appropriate if it
can be shown that a sufficient fraction of a fish population
would be protected by the combined effects of the fishing mortality
control rule and the marine reserves, and if such an increase
would not have other adverse impacts such as increased bycatch
of other species). The placement of artificial reefs in the
"sink areas" of the reserve (areas in which recruits originating
in the reserve are likely to take up residence) may help compensate
displaced fishers and make no-take reserves more palatable,
if research shows that such reefs can actually increase net
secondary (fish) production rather than simply attract fish
from other natural habitats. The success of artificial reefs
is likely to vary substantially from site-to-site, depending
on the mix of factors that limit fish production.
5. Allowing degraded habitats to recover.
Many marine systems such as coral reefs have a tremendous capacity
for self-repair, given sufficient water quality and relief from
chronic artificial disturbance. Marine protected areas which
eliminate all consumptive use are likely to help in ecosystem
restoration. Eliminating all access (including diving, snorkeling,
swimming, boating, etc.) except for research (to assess the
recovery) may be necessary in some cases.
6. Reducing gear conflicts.
Areas in which only certain types of gear are allowed can likely
have fishery and conservation benefits. No-bottom-trawl zones
can potentially protect demersal fish populations and bottom
habitat from the adverse impacts of trawling. Of course, such
areas would have very strong allocative effects, so policy efforts
will be needed to establish priority for more selective or less
habitat-damaging fishing techniques first.
7. Protecting sensitive life history stages.
Seasonal closures have been used in the past to protect spawning
aggregations. They are likely to be effective if spawning production
is limiting to a fish population. Many fish populations can
be limited by a number of different factors, including: prey
availability, habitat availability, competition, survivorship
of larvae or juveniles, metamorphosis, etc., so careful analysis
will be required to project the likelihood of success of seasonal
closures.
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